General, Organic, and Biological Chemistry, 3e (Timberlake)
20
Chapter 6
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Chemical Reactions and Quantities
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6.1
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Multiple-Choice Questions
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1)
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A chemical equation is balanced when
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A)
20
the total number of molecules is the same in reactants and products.
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B)
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the total number of ions is the same in reactants and products.
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C)
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the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products.
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D)
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the number of atoms of each element is the same in reactants and products.
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E)
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the charge on each atom is the same in reactants and products.
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20
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2)
20
Which of the following gives the balanced equation for this reaction?
K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3
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A)
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KPO4 + CaNO3 + KNO3
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B)
20
K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 3KNO3
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C)
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2 K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 6KNO3
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D)
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2 K3PO4 + 3Ca(NO3)2 → Ca3(PO4)2 + 6KNO3
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E)
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K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3
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20
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3)
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Which of the following correctly gives the best coefficients for the reaction below?
N2H4 + H2O2 → N2 + H2O
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A)
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1, 1, 1 ,1
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B)
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1, 2, 1, 4
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C)
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2, 4, 2, 8
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D)
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1, 4, 1, 4
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E)
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2, 4, 2, 4
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20
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4)
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What coefficient is placed in front of O2 to complete the balancing of the following equation?
C5H8 + ? O2 → 5CO2 + 4 H2O
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A)
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1
20
B)
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3
20
C)
20
5
20
D)
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7
20
E)
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9
20
20
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5)
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What is the coefficient of hydrogen, H2, when the following equation is balanced?
Al + H2SO4 → Al2(SO2)3 + ? H2
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A)
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1
20
B)
20
2
20
C)
20
3
20
D)
20
4
20
E)
20
5
20
20
20
Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction. Answer the question(s) that follow about this reaction.
C5H12 + ? O2 → ? CO2 + ? H2O
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6)
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What is the coefficient for oxygen in the balanced equation?
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A)
20
2
20
B)
20
4
20
C)
20
5
20
D)
20
6
20
E)
20
8
20
20
20
7)
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What is the coefficient for carbon dioxide in the balanced equation?
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A)
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2
20
B)
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4
20
C)
20
5
20
D)
20
6
20
E)
20
8
20
20
20
8)
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What is the coefficient for water in the balanced equation?
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A)
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2
20
B)
20
4
20
C)
20
5
20
D)
20
6
20
E)
20
8
20
20
20
9)
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In a ______reaction, two or more elements or compounds form one product.
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A)
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decomposition
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B)
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single replacement
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C)
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dehydration
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D)
20
double replacement
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E)
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combination
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20
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10)
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The following reaction takes place when an electric current is passed through water. It is an example of a ______reaction.
2 H2O → 2H2 + O2
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A)
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combination
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B)
20
single replacement
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C)
20
dehydration
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D)
20
decomposition
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E)
20
double replacement
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20
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11)
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Which of the following is an oxidation-reduction reaction?
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A)
20
CaCl2 + Na2SO4 → CaSO4 + 2NaCl
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B)
20
KOH + HNO3 → H2O + KNO3
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C)
20
N2 + O2 → 2NO
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D)
20
AgNO3 + NaCl → AgCl + NaNO3
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E)
20
Al2(SO4)3 + 6KOH → 2Al(OH)3 + 3K2SO4
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20
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12)
20
What is oxidized and what is reduced in the following reaction?
2Al(s) + 3Br2 (g) → 2AlBr3 (s)
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A)
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Al is oxidized and Br2 is reduced.
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B)
20
AlBr3 is reduced and Br2 is oxidized.
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C)
20
Al is reduced and Br2 is oxidized.
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D)
20
AlBr3 is reduced and Al is oxidized.
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E)
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AlBr3 is oxidized and Al is reduced.
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20
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13)
20
Which of the following describes an oxidation?
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A)
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loss of electrons or loss of oxygen
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B)
20
loss of electrons or gain of oxygen
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C)
20
loss of electrons or gain of hydrogen
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D)
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gain of electrons or gain of oxygen
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E)
20
gain of electrons or loss of H
20
20
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14)
20
In an oxidation-reduction reaction, the substance oxidized always
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A)
20
takes on oxygen atoms.
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B)
20
shows a loss of electrons.
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C)
20
gives up hydrogen atoms.
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D)
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shows a gain of electrons.
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E)
20
becomes a charged species.
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20
20
15)
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In this reaction, what is the substance oxidized?
Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g)
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A)
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chlorine
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B)
20
zinc chloride
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C)
20
hydrogen
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D)
20
Zn
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E)
20
oxygen
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20
20
16)
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In an oxidation-reduction reaction, the substance reduced always
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A)
20
takes on oxygen atoms.
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B)
20
shows a loss of electrons.
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C)
20
gives up hydrogen atoms.
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D)
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shows a gain of electrons.
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E)
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becomes a charged species.
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20
20
17)
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In this reaction, what is the coefficient for calcium oxide?
CaO(s) + CO2(g) → CaCO3(s)
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A)
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1
20
B)
20
2
20
C)
20
3
20
D)
20
4
20
E)
20
5
20
20
20
18)
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In this reaction, what is the correct coefficient for sodium chloride?
Pb(NO3)2 (aq) + NaCl(aq) → PbCl2 (s) + NaNO3 (aq)
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A)
20
1
20
B)
20
2
20
C)
20
3
20
D)
20
4
20
E)
20
5
20
20
20
19)
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In the following reaction, what is the correct coefficient for aluminum chloride?
Al(s) + Cl2 (g) → AlCl3 (s)
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A)
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1
20
B)
20
2
20
C)
20
3
20
D)
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4
20
E)
20
5
20
20
20
20)
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What is the classification for this reaction?
SO3 (g) + H2O (l) → H2SO4 (l)
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A)
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decomposition
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B)
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combination
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C)
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replacement
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D)
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double replacement
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E)
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oxidation reduction
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20
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21)
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The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction?
2C(s) + O2 (g) → 2CO(g)
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A)
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single replacement
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B)
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double replacement
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C)
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combination
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D)
20
catalytic
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E)
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endothermic
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20
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22)
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For the following reaction, what is the correct coefficient for the H2?
Fe(s) + HCl(aq) → FeCl3 (aq) + H2 (g)
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A)
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1
20
B)
20
2
20
C)
20
3
20
D)
20
4
20
E)
20
5
20
20
20
23)
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What is the classification for this unbalanced reaction?
Fe + HCl → FeCl3 + H2
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A)
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dehydration
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B)
20
combination
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C)
20
decomposition
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D)
20
single replacement
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E)
20
double replacement
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20
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24)
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In any balanced chemical equation, the number of each type of atom on both sides of the equation is
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A)
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doubled.
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B)
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the same.
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C)
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decreased by one.
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D)
20
increased by one.
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E)
20
dependent on the temperature.
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20
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25)
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How many molecules of water, H2O, are present in 75.0 g of H2O?
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A)
20
75.0 molecules
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B)
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4.17 molecules
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C)
20
7.53 x 1024 molecules
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D)
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2.51 x 1024 molecules
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E)
20
5.02 x 1024 molecules
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20
20
26)
20
How many hydrogen atoms are present in 75.0 of g H2O?
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A)
20
75.0 atoms
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B)
20
4.17 atoms
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C)
20
7.53 x 1024 atoms
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D)
20
2.51 x 1024 atoms
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E)
20
5.02 x 1024 atoms
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20
20
27)
20
How many moles of water, H2O, are present in 75.0 g of H2O?
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A)
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4.41 moles
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B)
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4.17 moles
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C)
20
75.0 moles
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D)
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7.50 moles
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E)
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1.35 x 103 moles
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20
20
28)
20
How many moles of iron are present in 3.15 x 1024 atoms of iron?
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A)
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5.23 moles
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B)
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1.90 moles
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C)
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292 moles
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D)
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0.523 moles
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E)
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1.90 x 1048 moles
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20
20
29)
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One mole of particles of any substance contains how many particles?
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A)
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106
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B)
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3 x 10-10
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C)
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3 x 1010
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D)
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6.02 x 1023
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E)
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6.02 x 10-23
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20
20
30)
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Avogadro's number is the number of
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A)
20
particles in 1 mole of a substance.
20
B)
20
amu in 1 mole of a substance.
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C)
20
grams in 1 mole of a substance.
20
D)
20
moles in 6.02 x 1023 grams of an element.
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E)
20
moles in 6.02 x 1023 amu of an element.
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20
20
31)
20
The molar mass of potassium is
20
A)
20
19 g.
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B)
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31.0 g.
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C)
20
6.02 x 1023 grams.
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D)
20
39.1 g.
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E)
20
15g.
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20
20
32)
20
One mole of helium gas weighs
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A)
20
1.00 g.
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B)
20
2.00 g.
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C)
20
3.00 g.
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D)
20
4.00 g.
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E)
20
8.00 g.
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20
20
33)
20
0.100 mole of lithium weighs
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A)
20
3.00 g.
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B)
20
0.300 g.
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C)
20
6.94 g.
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D)
20
0.694 g.
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E)
20
0.700 g.
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20
20
34)
20
Calculate the molar mass of potassium chloride, KCl.
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A)
20
74.6 g
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B)
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54.5 g
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C)
20
6.74 g
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D)
20
67.4 g
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E)
20
19.0 g
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20
20
35)
20
What is the molar mass of copper(II) sulfate, CuSO4?
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A)
20
16.0 g
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B)
20
63.6 g
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C)
20
111.6 g
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D)
20
159.6 g
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E)
20
319.2 g
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20
20
36)
20
Calculate the molar mass of magnesium chloride, MgCl2.
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A)
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24.3 g
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B)
20
95.2 g
20
C)
20
125.9 g
20
D)
20
59.8 g
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E)
20
70.0 g
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20
20
37)
20
What is the molar mass of sodium phosphate, Na3PO4?
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A)
20
119.0 g
20
B)
20
308.0 g
20
C)
20
164.0 g
20
D)
20
226.0 g
20
E)
20
354.0 g
20
20
20
38)
20
How many moles of carbon atoms are there in 0.500 mole of C2H6?
20
A)
20
0.500 moles
20
B)
20
1.00 moles
20
C)
20
3.00 moles
20
D)
20
6.02 x 1023 moles
20
E)
20
4.00 moles
20
20
20
39)
20
What is the molar mass of sucrose (C12H22O11)?
20
A)
20
29.0 g
20
B)
20
50.2 g
20
C)
20
210 g
20
D)
20
342 g
20
E)
20
182 g
20
20
20
40)
20
One mole of neon atoms has a mass of
20
A)
20
6.02 x 1023 grams.
20
B)
20
14.0 g.
20
C)
20
10.0 g.
20
D)
20
20.2 g.
20
E)
20
30.2 g.
20
20
20
41)
20
The molar mass of C3H8O2 is
20
A)
20
76.0 g.
20
B)
20
60.0 g.
20
C)
20
29.0 g.
20
D)
20
69.0 g.
20
E)
20
52.0 g.
20
20
20
42)
20
The molar mass of calcium hydroxide, Ca(OH)2, is
20
A)
20
58.1 g.
20
B)
20
57.1 g.
20
C)
20
74.1 g.
20
D)
20
114.2 g.
20
E)
20
38.0 g.
20
20
20
43)
20
What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?
20
A)
20
71.3 g
20
B)
20
118.3 g
20
C)
20
150.3 g
20
D)
20
214.3 g
20
E)
20
262.9 g
20
20
20
44)
20
4.00 moles of sodium have a mass of
20
A)
20
4.60 g.
20
B)
20
11.0 g.
20
C)
20
23.0 g.
20
D)
20
44.0 g.
20
E)
20
92.0 g.
20
20
20
45)
20
How many moles of K2SO4 are in 15.0 g of K2SO4?
20
A)
20
0.172 moles
20
B)
20
2.61 x 103 moles
20
C)
20
0.111 moles
20
D)
20
0.0861 moles
20
E)
20
0.119 moles
20
20
20
46)
20
3.00 moles of NO2 have a mass of
20
A)
20
138 g.
20
B)
20
46.0 g.
20
C)
20
30.0 g.
20
D)
20
90.0 g.
20
E)
20
45.0 g.
20
20
20
47)
20
How many grams of Fe2O3 are there in 0.500 mole of Fe2O3?
20
A)
20
79.8 g
20
B)
20
35.9 g
20
C)
20
63.8 g
20
D)
20
51.9 g
20
E)
20
160. g
20
20
20
48)
20
How many grams of glucose (C6H12O6) are in 3.55 moles of glucose?
20
A)
20
180. g
20
B)
20
639 g
20
C)
20
103 g
20
D)
20
426 g
20
E)
20
50.7 g
20
20
20
49)